Numerical simulation and analysis of cavitating Flow around hydrofoil and in injector nozzle

Abstract

Cavitation occurs in flow regions where the hydrodynamic effect reduces the local pressure newlinebelow the saturation vapor pressure of the liquid, causing the formation of vapor bubbles. When newlinethese vapor bubbles enter the region of higher pressure, they collapse violently producing newlineenough force to damage the solid body. In case of hydrofoils, cavitation can affect the newlinehydrodynamic and structural performance potentially. In injector nozzles, cavitation can cause newlinea fuel injection instability and decreased fuel efficiency. Cavitation on hydrofoils and nozzles newlinemainly depends on the flow parameters, shape and material of the hydrofoil or nozzle. In the newlinepresent work to study the cavitation phenomenon three different studies have been made on newlinehydrofoils and in injector nozzle. In first part of the work, the performance of two different newlinecavitation model and four different turbulence models is compared with the available newlineexperimental data on cavitating NACA4412 and Clark-y hydrofoil in terms of lift coefficient, newlinedrag coefficient, Strouhal number and velocity profiles using ANSYS Fluent. Among all the newlineturbulence models, the Realizable k-and#120598; turbulence was found to be more accurate, whereas the newlineZwart-Gerber-Belamri cavitation model is found to be more reliable. Using the Realizable k-and#120598; newlineand Zwart-Gerber-Belamri cavitation model, the research was further extended to study the newlinehydrodynamic and structural performance of 3D stainless steel MHKF-180 and NACA4418 newlinecavitating hydrofoils using one-way fluid structure interaction (FSI). The simulation is newlineperformed at a chord-based Reynolds number, Re = 750000, for different cavitation numbers newlineand angles of attack. On comparing the hydrodynamic performance of both the foils, in terms newlineof lift coefficient, MHKF-180 found to perform better than NACA4418 under the cavitating newlinecondition. Whereas, from structural point of view, the MHKF-180 shows larger tip deformation newlineand von Mises stress than NACA4418 hydrofoil. Further, in the last part of the work, the newlinenumerical investigat